looking for a recomendation on empty can with a mounting depth of at least 4" to mount a 6.5" HLCD driver. Would prefer to use the mastercraft tower mount and would prefer a metalic finish, but am open to others.

Bulletlines.com sells aluminum cans for a reasonable price. Their website has them for $186 for a pair of singles or $197 for a pod that holds two (so basically $400 if you need 4 cans). But they have an eBay store where they sell the same cans for a lot less. I got mine for $130 per pair of single cans and that included shipping. That is $56 less than their site, for the same product.